This blog was written by Peter Tse, Principal Design Consultant for BSRIA’s Sustainable Construction Group

Back in May 2010, Innovate UK (formally TSB) embarked on four year programme, providing £8m funding to support case study investigations of domestic new build and non-domestic new build and major refurbishment projects. In total the programme has supported 100 successful projects to provide a significant body of work, that provide insights on the performance of various design strategies, building fabric, target performances, construction methods and occupancy patterns, handover and operational practices. This work will be shared across the industry providing evidence based information, increasing industry understanding to support closing the loop between theory and practice, ensuring the delivery of zero carbon new buildings is more readily and widely achievable.

Currently project teams are concluding their investigations and collating their findings, and dissemination of the results of the programme will begin in earnest in the first half of 2015. However, as the programme has progressed, there are some consistent themes that are emerging. Focussing on the non-domestic projects, I will address a couple of these emerging themes.

The first is around adopting innovative building systems to deliver low energy consumption and comfortable conditions, and unintended consequences associated with these technologies. This covers a broad spectrum of building technologies including solar thermal, heat pumps, biomass boilers, earth tubes, rainwater harvesting, controls and natural ventilation strategies. Innovation in its essence will have some inherent teething problems, which is often overlooked in the charge towards reaching our carbon reduction targets. The obvious default stance is to specify proven and reliable technologies which are delivered by a team that is familiar with the technology, but our journey towards delivering true low carbon building in operation would inevitably be prolonged.

An additional level of complexity can be added with innovative systems; one healthcare facility introduced solar thermal and a combined heat and power (chp) unit, to supplement natural gas fired boilers for heating and hot water requirements. With several sources of heat complexity is added to the control strategy, trying to strike a balance between changing heat demands of the building and optimisation of the system. This complexity, coupled with a requirement for increased operator understanding often leads to system underperformance.

The practicalities, maintenance and associated costs of innovative systems is seldom fully realised by clients. An office reported success of the rainwater harvesting system, but were surprised at the frequency of filter changes to mitigate the system being blocked. Another office had to regulate a fan associated with earth tube ventilation system, as running at a higher speed caused too much noise for occupants. A school had ingress of water to an underground wood chip store rendering the biomass boiler idle for significant periods. A hotel employed automatic external blinds which retracted in windy conditions to avoid damage, thus offering no shade to occupants during sunny, windy days.

It is clear a reality checking process is required for design decisions to mitigate such matters. BSRIA’s Pitstopping guide, which resides within the Soft Landings framework describes a process that allows construction teams to periodically reconsider critical design issues by focusing on the perspective of the end user. This also provides an opportunity for the client to understand the full ramifications of implementing innovative building systems for a more informed decision, and to align client expectations.

The second theme involves the process in delivering innovative technologies, with a particular a focus on commissioning and handover. The commissioning period residing at the end of the build process is often susceptible to being squeezed. When the decision has been taken to adopt an innovative building system, there is increased pressure during commissioning to ensure the system is operating as intended. With the additional complexity associated with innovative technologies, it is vital the commissioning time is adequate to complete comprehensive scenario based testing; how is hot water delivered if the solar thermal does not provide a contribution, how is the building operator alerted the status of the system, how can the operator diagnose the problem, how long can the system operate without the solar thermal contribution without major detrimental effects etc. To ease the burden on the commissioning period, it is clear commissioning should not be afterthought, but an integral part of the build process.

The commissioning period also signals a time where many of the stakeholders with tacit knowledge of the innovative building systems have changing responsibilities. It is vital this knowledge is captured for users before the opportunity is lost. Building manuals, user guides and logbooks need to be completed so users can relate to their building environment, understand control of the environment and capture major alterations.

Many projects reported that guidance for both users and operators was often lacking, with several BPE teams developing guidance as part of their projects to support users. Commonly BPE teams have also struggled to find initial design intent and operational strategy associated with innovative technologies, highlighting the importance of handover documentation. Training of users is another key element to knowledge continuity, but several projects reported changes in staff being a core reason for innovative systems underperforming, as documentation was not kept up to date. The value of clear concise user guidance is evident; BSRIA’s Building Manual and Building User Guides helps individuals responsible for creating building logbook and user guides.

Since then BS 1192-4 has been published, leaving just the Digital Plan of Work and Classification elements to be completed. As reported previously, these were the subject of a TSB-funded competition and I thought it would be useful to give an overview of how the competition went and where it is now. This is a fundamental piece of work that is set to have a huge impact on BIM in the UK and it is vital that as much of the industry as possible has an awareness of what is happening, and get involved wherever possible to help make it a success.

The competition brief was developed, with industry consultation, and has been administered via the Innovate UK (formerly TSB) SBRI programme under the title “A digital tool for building information modelling”.

The competition process involved two phases – Phase 1was a feasibility study, with organisations or consortia invited to submit proposals with funding of up to £50k (including VAT) available to each. Three teams were awarded these phase one contracts:

CIBSE on behalf of a group of industry professional bodies known as C8, consisting Association for Project Management (APM), British Institute of Facilities Management (BIFM), Chartered Institution of Building Services Engineers (CIBSE), Chartered Institute of Building (CIOB), Institution of Civil Engineers (ICE), Institution of Structural Engineers (IStructE), Royal Institute of British Architects (RIBA) and Royal Institution of Chartered Surveyors.

On completion of Phase one, two of these submitted bids for Phase 2 – RIBA Enterprises Limited and BRE Global Limited, and RIBA Enterprises Limited was awarded the single Phase two contract.

At the time of writing, the results of the Phase two competition had not been posted on the Innovate UK website so it has not been possible to compare what RIBA Enterprises has said it will deliver with the functional specification.

As RIBA Enterprises has developed Uniclass2, which it uses for some of its other software tools, it is probably safe to assume that the classification solution delivered as part of this competition will be based on that format. That being the case it will be interesting to see how Uniclass2 is developed to cover all necessary instances, and not just those which may occur within the 3D model. The classification system needs to be capable of capturing everything which may be held within the common data environment (CDE) in order to make the objectives of the standards such as PAS 1192-2 and PAS 1192-3 a reality – the PIM during construction and AIM during operation being the sole sources of information for further use, having been verified and validated against the EIRs and OIRs.

Many experienced BIM practitioners recognise the need for a comprehensive classification system to make information available throughout the life of an asset, letting it be used time and again rather than having to recreate it, and this project could make this a reality. However, careful thought needs to go into it to make sure that everything that needs to be classified can be, and in a way that can be understood.

The emerging results for more than 50 non-domestic buildings have now been analysed by BSRIA to look at what works well, and when things don’t, why this is the case. It’s always difficult to generalise based on such a diverse building stock, ownership profile, procurement route, supply chain capabilities, and operational approach, but its clear that in many of the buildings there is a significant performance gap between design intent, and realised performance. Analysis of such data is always a challenge. How does one attribute, for instance, any shortfall in performance between the specification, design, construction, commissioning process, and to operational issues such as sub-optimal energy management and / or changes in operating regime such as an extension in occupancy hours.

However one lesson inferred from the analysis is that with some low carbon (and / or energy) buildings one of the unintended consequences is that sometimes the building has been finely “tuned” to minimise carbon (and / or energy), and capital costs at the expense of the building’s resilience in the face of, say, changing patterns of use or internal gains. Put simply, if a building has been engineered to reduce energy and or carbon for a particular set of operating conditions, and one way of achieving this is to simply size ventilation, and air conditioning plant in line with those conditions, what happens if say internal gains increase as a result of higher occupancy loading? In practice it is found that some environmental designs lack the flexibility to cope with changes in business use because of limitations built into their design. This happens with more conventional buildings, with the difference for environmental buildings being more pronounced because the design in many cases is more finely “tuned” as we move ever closer to “near zero”, or “very low” energy / carbon buildings.

BSRIA’s experience identifies many of the good practices required to ensure environmental buildings work well, and also the impact of poor practice. Overly sensitive design is one cause of poor performance in practice. So the question is why do some clients and their design team include a sensitivity analysis to design services and size plant so as to ensure resilience, whereas others adopt an approach best characterised by “lowest capital, highest environmental ranking, never mind about actual performance in use”? The likely answers are complex. Those found by others like Latham and Egan come to mind for some instances: informed clients recruit supply chains who know their business, and both understand implications of design decisions; another is the chasm which can often occur between those who specify, procure, and lease buildings, and those who occupy and manage them. Perhaps a third is that once a building has been occupied, too seldom is thought given to how the building will actually work in the face of changes in occupant requirements.

The question for BSRIA is how we can provide a steer and guidance to our members and the industry as to how best to ensure that we build the next generation of environmentally sensitive buildings to be even more resilient in the face of likely changes those buildings will face over their lifetime. A building which has a very low carbon and / or energy design use, but which fails to provide a productive environment in the face of foreseeable changes in operating conditions can’t really be described as “sustainable”.

This blog was written by BSRIA’s Chief Executive, Julia Evans. For more information about BPE you can visit our website or visit the TSB’s BPE pages where you can look at case studies and methods of BPE (you may need to register to access these).

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